Evolution from AGB to planetary nebula in the MSX survey

Abstract

We investigate the evolution of oxygen- and carbon-rich AGB stars, post-AGB objects, and planetary nebulae using data collected mainly from the MSX catalogue. Magnitudes and colour indices are compared with those calculated from a grid of synthetic spectra that describe the post-AGB evolution beginning at the onset of the superwind. We find that carbon stars and OH/IR objects form two distinct sequences in the (K-[8.3])x([8.3]-[14.7]) MSX colour diagram. OH/IR objects are distributed in two groups: the bluest ones are crowded near [14.7]-[21.3]=1 and [8.3]-[14.7]=2, and a second, redder group is spread over a large area in the diagram, where post-AGB objects and planetary nebulae are also found. High mass-loss rate OH/IR objects, post-AGB stars, and planetary nebulae share the same region in the (K-[8.3])x([8.3]-[14.7]) and [14.7]-[21.3]x([8.3]-[14.7]) colour-colour diagrams. This region in the diagram is clearly separated from a bluer one where most OH/IR stars are found. We use a grid of models of post-AGB evolution, which are compared with the data. The gap in the colour-colour diagrams is interpreted as the result of the rapid trajectory in the diagram of the stars that have just left the AGB.

11 pages, 5 postscript figures, LaTeX, uses Astronomy and Astrophysics macro aa.cls, graphicx package, to be published in Astronomy and Astrophysics, Also available at: http://www.astro.iag.usp.br/~maciel

References in corpus (6)

• The Population of the Galactic Plane as Seen by MSX
• Bipolar outflows in OH/IR stars
• The ATCA/VLA OH 1612 MHz survey. III. Northern Galactic Plane
• OH-selected AGB and post-AGB objects I.Infrared and maser properties
• The spectral evolution of post-AGB stars
• OH-selected AGB and post-AGB stellar objects II.Blue versus red evolution off the AGB

Cited by in corpus (15)

• The Red MSX Source Survey: the Massive Young Stellar Population of our Galaxy
• Near-Infrared Photometry of Carbon Stars
• Infrared Photometry and Evolution of Mass-Losing AGB Stars I. Carbon Stars Revisited
• A CO survey in planet-forming disks: characterizing the gas content in the epoch of planet formation
• New Young Planetary Nebulae in IPHAS
• Infrared two-colour diagrams for AGB stars using AKARI, MSX, IRAS and NIR data
• MSX versus IRAS Two-Color Diagrams and the CSE-Sequence of Oxygen-Rich Late-Type Stars
• The Bulge Asymmetries and Dynamical Evolution (BAaDE) SiO Maser Survey at 86 GHz with ALMA
• Carbon- and Oxygen-rich Asymptotic Giant Branch (AGB) stars in the Bulge Asymmetries and Dynamical Evolution (BAaDE) survey
• Insight into the OH polarimetric structure of OH 26.5+0.6
• Identification of late-type stars of class I
• A distance scale of planetary nebulae based on mid-infrared data
• Chemical composition of A--F type post-AGB candidates
• Infrared color separation between thin-shelled oxygen-rich and carbon-rich AGB stars
• Long-period maser-bearing Miras in the Galactic center: period-luminosity relations and extinction estimates